Pancreatitis is an inflammatory disease of the pancreas. The U.S. alone sees over 300,000 hospital admissions for acute pancreatitis annually with costs exceeding $2B. However, there is currently no specific therapy for this disease, a lamentable situation arising from our incomplete understanding of its pathophysiology. In part, this situation can be ascribed to the fact that, due to the non-availability of human acinar tissue for experimentation, most of our current knowledge of the pathophysiology of pancreatitis arises from experimental animal models. However, our preliminary data as well as other published studies indicate that there are significant differences in the physiology and pathobiology of acinar cells between humans and rodents. Such information accentuates the urgent need to re-access data generated from rodent models in models which truly reflect human disease. This is further reinforced by the negative outcomes of the clinical trials using the information learnt from experimental animal models. Recently, the advent of endocrine pancreas transplantation programs has made healthy human exocrine pancreatic tissue from donor organs available for in vitro experiments. There are only a handful of such transplantation centers in the US, and to successfully harvest and study human acini in-vitro requires an experienced exocrine pancreas lab. At our center we are uniquely poised to fulfill both pre-requisites. In the current proposal, we intend to utilize acinar cells harvested from pancreata of healthy donors to study and validate basic tenets in the physiology and pathophysiology of human exocrine pancreas. The studies proposed in the current grant will first confirm the tenets of stimulus secretion coupling in human acinar cells, since these principles form the backbone of studies on pathophysiology of pancreatitis. Next, the pathophysiology of early acute pancreatitis will be studied in two different in vitro models of acute pancreatitis in human acinar cells: hyperstimulation model and the more clinically apt model of biliary pancreatitis. We believe that the data generated through the experiments proposed in the current grant proposal will form the basis, in the future, of directed research applicable to the pathophysiology of acute pancreatitis in humans and lead to accelerated development of specific therapy for its prevention and treatment.